WASHINGTON (AP) — President Barack Obama’s pick to run the Pentagon says he will seek better use of taxpayer dollars but that Congress must bring stability back to the military’s budget.

Ashton Carter, in prepared remarks for his Senate confirmation hearing Wednesday, acknowledges that the Defense Department must end wasteful practices that undermine public confidence even as he criticizes the automatic spending cuts known as sequestration.

“I cannot suggest support and stability for the defense budget without at the same time frankly noting that not every defense dollar is spent as well as it should be,” Carter says in remarks prepared for his opening statement to the Armed Services Committee.

“The taxpayer cannot comprehend, let alone support, the defense budget when they read of cost overruns, lack of accounting and accountability, needless overhead and the like,” he adds in prepared remarks obtained by The Associated Press.

Though Carter is expected to face questions about Iraq and other hot spots during his Senate appearance, his confirmation is widely expected.

Sen. John McCain, Republican chairman of the Senate Armed Services Committee, praised Carter as an honest, hard-working and respected defense professional, and said he hoped he would push back on any attempt by the White House to micromanage the Defense Department or over-centralize U.S. foreign and defense policies.

McCain used his opening statement to blast what he called the “mindless mechanism of sequestration,” automatic spending cuts that are squeezing the Pentagon budget.

“Despite the growing array of complex threats to our security, we are on track to cut $1 trillion out of America’s defense budget by 2021,” said McCain, who says Carter likely will be confirmed. “Readiness is falling across the services, and morale is falling right along with it.”

“Army and Marine Corps end-strength is dropping dangerously low. The Air Force is the oldest and the smallest it has ever been. The Navy’s fleet is shrinking to pre-World War I levels,” said McCain, a Vietnam era prisoner of war.

Nominated by President Barack Obama to become the fourth Pentagon chief of his administration, he is experienced in a wide range of national security issues.

The Philadelphia native served twice previously in Obama’s Pentagon, most recently as deputy defense secretary from 2011 to 2013. He was assistant secretary of defense for international security policy during the administration of President Bill Clinton.

Unlike his predecessors over the past 30-plus years, Carter has served neither in the military nor in Congress. The last defense secretary without experience in uniform or national politics was Harold Brown, who was appointed by President Jimmy Carter and led the Pentagon from 1977 to 1981.

In his prepared remarks, Ashton Carter says the automatic spending cuts are risky to U.S. defense. The man he would replace as defense secretary, Chuck Hagel, has said that if sequestration is not eliminated the Pentagon probably would have to rewrite its defense strategy.

“It introduces turbulence and uncertainty that are wasteful, and it conveys a misleading diminished picture of our power in the eyes of friends and foes alike,” Carter says.

Noting his longstanding interest in reforming the Pentagon’s must-criticized spending habits, Carter says he will attack the issue head on.

“If confirmed as secretary of defense I pledge to make needed changes in the Pentagon, but also to seek support from Congress, because in the end I know that Congress holds the power of the purse,” he says.

Carter, 60, is a physicist by training and a highly regarded thinker on strategy, budgets and policy. When Obama announced his nomination on Dec. 5, the president credited Carter with a “unique blend of strategic perspective and technical know-how.” He is steeped in the intricacies of missile defense, U.S. nuclear weapons, U.S.-China relations and the evolution of North Korea’s nuclear program.

Less clear is whether Carter will find more success than Hagel in gelling with Obama’s inner circle. The president’s relationship with the Pentagon has often been strained, with some officials in the department saying Obama views the military skeptically and centralizes decision making in the West Wing.

Hagel, a Republican and a former senator from Nebraska, was tapped for the Pentagon post in part because he was seen as someone who would largely acquiesce to the White House, though he, too, is said to have grown frustrated, particularly with the policymaking process overseen by national security adviser Susan Rice.

Two of Obama’s previous Pentagon chiefs, Robert Gates and Leon Panetta, have publicly aired their grievances with what they saw as White House micromanagement.

Carter would inherit a Pentagon wrestling with the Islamic State militant threat in Iraq and Syria, an unsettled course for Afghanistan, Russian provocations in Ukraine and an uncertain outlook for the defense budget.

He is likely to face questions on these and other issues at his confirmation hearing, including the threat posed by Iran’s nuclear ambitions and doubts about Obama’s push to close the U.S. prison at Guantanamo Bay, Cuba, for terror suspects.

In response to written questions from the Armed Services Committee prior to his hearing, Carter said he would consider changing plans for withdrawing all U.S. troops from Afghanistan by the end of 2016 if security conditions worsen. About 10,600 U.S. troops remain in Afghanistan.

Carter also said he is aware of reports that Islamic State militants may try to expand into Afghanistan, and that he will work with coalition partners to ensure that does not happen.

McCain, R-Ariz., has repeatedly questioned the wisdom of setting and announcing a hard end date to the U.S. presence in Afghanistan.

A relatively unknown figure nationally, Carter would be among the younger defense secretaries in recent years and the first to come of age after the Vietnam War. He received undergraduate degrees in physics and medieval history at Yale University and earned his doctorate in theoretical physics at Oxford University as a Rhodes scholar.